Acute effects of co-infusion of peptide YY (3[n]36) and glucagon-like peptide-1 on insulin secretion and insulin sensitivity

2013 ◽  
pp. 1-1
Author(s):  
Tricia Tan ◽  
Victoria Salem ◽  
Rachel Troke ◽  
Akila De Silva ◽  
Ali Alsafi ◽  
...  
1999 ◽  
Vol 277 (6) ◽  
pp. E996-E1004 ◽  
Author(s):  
Bo Ahrén ◽  
Giovanni Pacini

We examined the dose-related net effects of glucagon-like peptide 1 (GLP-1) on insulin secretion, insulin sensitivity, and glucose disposal as derived from the minimal model of glucose disappearance in anesthetized mice. GLP-1 dose dependently potentiated insulin secretion after glucose administration, with the half-maximal effect at 1 nmol/kg. GLP-1 also dose dependently reduced the area under the glucose curve (AUCglucose) and increased the glucose elimination rate (KG) but did not affect the glucose effectiveness (SG). Furthermore, the insulin sensitivity index (SI) was reduced after administration of GLP-1. Because insulin secretion was stimulated to a larger degree than SI was reduced, the peptide increased the global disposition index (GDI = AUCinsulin × SI). Matching plasma insulin levels after GLP-1 by exogenous insulin reproduced the influences of GLP-1 on AUCglucose, KG, SI, and GDI. Finally, the GLP-1 receptor antagonist exendin-3-(9—39) inhibited the actions of GLP-1. We conclude that GLP-1 increases glucose tolerance in the mouse mainly by potently stimulating insulin secretion.


2006 ◽  
Vol 191 (1) ◽  
pp. 93-100 ◽  
Author(s):  
J C Parker ◽  
K S Lavery ◽  
N Irwin ◽  
B D Green ◽  
B Greer ◽  
...  

Glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are important enteroendocrine hormones that are rapidly degraded by an ubiquitous enzyme dipeptidyl peptidase IV to yield truncated metabolites GIP(3–42) and GLP-1(9–36)amide. In this study, we investigated the effects of sub-chronic exposure to these major circulating forms of GIP and GLP-1 on blood glucose control and endocrine pancreatic function in obese diabetic (ob/ob) mice. A once daily injection of either peptide for 14 days had no effect on body weight, food intake or pancreatic insulin content or islet morphology. GLP-1(9–36)amide also had no effect on plasma glucose homeostasis or insulin secretion. Mice receiving GIP(3–42) exhibited small but significant improvements in non-fasting plasma glucose, glucose tolerance and glycaemic response to feeding. Accordingly, plasma insulin responses were unchanged suggesting that the observed enhancement of insulin sensitivity was responsible for the improvement in glycaemic control. These data indicate that sub-chronic exposure to GIP and GLP-1 metabolites does not result in physiological impairment of insulin secretion or blood glucose control. GIP(3–42) might exert an overall beneficial effect by improving insulin sensitivity through extrapancreatic action.


2007 ◽  
Vol 292 (6) ◽  
pp. E1808-E1814 ◽  
Author(s):  
K. Thomaseth ◽  
A. Pavan ◽  
G. Pacini ◽  
B. Ahrén

Glucagon-like peptide-1 (GLP-1) plays a significant role in glucose homeostasis through its incretin effect on insulin secretion. However, GLP-1 also exhibits extrapancreatic actions, and in particular its possible influences on insulin sensitivity are controversial. To study the dynamic action of GLP-1 on insulin sensitivity, we applied advanced statistical modeling methods to study glucose disappearance in mice that underwent intravenous glucose tolerance test with administration of GLP-1 at various dose levels. In particular, the minimal model of glucose disappearance was exploited within a population estimation framework for accurate detection of relationships between glucose disappearance parameters and GLP-1. Minimal model parameters were estimated from glucose and insulin data collected in 209 anesthetized normal mice after intravenous injection of glucose (1 g/kg) alone or with GLP-1 (0.03–100 nmol/kg). Insulin secretion markedly increased, as expected, with increasing GLP-1 dose. However, minimal model-derived indexes, i.e., insulin sensitivity and glucose effectiveness, did not significantly change with GLP-1 dose. Instead, fractional turnover rate of insulin action [P2 = 0.0207 ± 24.3% (min) at zero GLP-1 dose] increased steadily with administered GLP-1 dose, with significant differences at 10.4 nmol/kg (P2 = 0.040 ± 15.5%, P = 0.0046) and 31.2 nmol/kg (P2 = 0.050 ± 29.2%, P = 0.01). These results show that GLP-1 influences the dynamics of insulin action by accelerating insulin action following glucose challenge. This is a novel mechanism contributing to the glucose-lowering action of GLP-1.


2019 ◽  
Vol 316 (5) ◽  
pp. G574-G584 ◽  
Author(s):  
Charlotte Bayer Christiansen ◽  
Samuel Addison Jack Trammell ◽  
Nicolai Jacob Wewer Albrechtsen ◽  
Kristina Schoonjans ◽  
Reidar Albrechtsen ◽  
...  

A large number of glucagon-like-peptide-1 (GLP-1)- and peptide-YY (PYY)-producing L cells are located in the colon, but little is known about their contribution to whole body metabolism. Since bile acids (BAs) increase GLP-1 and PYY release, and since BAs spill over from the ileum to the colon, we decided to investigate the ability of BAs to stimulate colonic GLP-1 and PYY secretion. Using isolated perfused rat/mouse colon as well as stimulation of the rat colon in vivo, we demonstrate that BAs significantly enhance secretion of GLP-1 and PYY from the colon with average increases of 3.5- and 2.9-fold, respectively. Furthermore, we find that responses depend on BA absorption followed by basolateral activation of the BA-receptor Takeda-G protein-coupled-receptor 5. Surprisingly, the apical sodium-dependent BA transporter, which serves to absorb conjugated BAs, was not required for colonic conjugated BA absorption or conjugated BA-induced peptide secretion. In conclusion, we demonstrate that BAs represent a major physiological stimulus for colonic L-cell secretion.NEW & NOTEWORTHY By the use of isolated perfused rodent colon preparations we show that bile acids are potent and direct promoters of colonic glucagon-like-peptide 1 and peptide-YY secretion. The study provides convincing evidence that basolateral Takeda-G protein-coupled-receptor 5 activation is mediating the effects of bile acids in the colon and thus add to the existing literature described for L cells in the ileum.


2000 ◽  
Vol 279 (5) ◽  
pp. G925-G930 ◽  
Author(s):  
G. Cuche ◽  
J. C. Cuber ◽  
C. H. Malbert

The aim of this study was to evaluate the nervous and humoral pathways involved in short-chain fatty acid (SCFA)-induced ileal brake in conscious pigs. The role of extrinsic ileal innervation was evaluated after SCFA infusion in innervated and denervated Babkin's ileal loops, and gastric motility was measured with strain gauges. Peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) concentrations were evaluated in both situations. The possible involvement of absorbed SCFA was tested by using intravenous infusion of acetate. Ileal SCFA infusion in the intact terminal ileum decreased the amplitude of distal and terminal antral contractions (33 ± 1.2 vs. 49 ± 1.2% of the maximal amplitude recorded before infusion) and increased their frequency (1.5 ± 0.11 vs. 1.3 ± 0.10/min). Similar effects were observed during SCFA infusion in ileal innervated and denervated loops (amplitude, 35 ± 1.0 and 34 ± 0.8 vs. 47 ± 1.3 and 43 ± 1.2%; frequency, 1.4 ± 0.07 and 1.6 ± 0.06 vs. 1.1 ± 0.14 and 1.0 ± 0.12/min). Intravenous acetate did not modify the amplitude and frequency of antral contractions. PYY but not GLP-1 concentrations were increased during SCFA infusion in innervated and denervated loops. In conclusion, ileal SCFA inhibit distal gastric motility by a humoral pathway involving the release of an inhibiting factor, which is likely PYY.


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